Re: [libvirt-users] Live migration process in src/qemu_driver.ca
On 03/20/2014 10:05 AM, Faizul Bari wrote:
Hello,
I have been trying to track different phases of a live migration process. I
am using libvirt with qemu-kvm. I am issuing migration commands using
virsh.
Now, I want to measure the time spent in each phase of live migration,
e.g., pre-copy and stop-copy. I stumbled upon the file qemu_driver.c. It
has functions like
qemudDomainMigratePrepare2
qemudDomainMigratePerform
qemudDomainMigrateFinish2
These functions perform different handshakes between the two libvirt
ends of the migration. However, the entire migration is done by a
single qemu monitor command, and it is that monitor command that further
divides the work into phases such as pre-copy and stop-copy.
I want to know whether qemudDomainMigratePerform and
qemudDomainMigrateFinish2 directly map to the pre-copy and stop-copy phase?
or the qemudDomainMigratePerform function performs both of them?
The MigratePerform function is the one place that calls the qemu monitor
command. I know there have been proposals upstream in qemu to add
additional statistics in 'query-migrate' monitor command; perhaps there
is still more work needed in libvirt to grab those additional statistics
in a manner that can be exposed to the user.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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